Static analysis

Question 1

What is newtons first law in the linear sense

Answer 1

An object at rest tends to stay at rest and an object in uniform motion tends to stay in uniform motion unless acted upon by a net external force.

Question 2

What is newtons first law in an angular sense

Answer 2

a body will maintain a constant state of angular motion unless acted on by a net external torque

Question 3

What is equilibirum

Answer 3

When the sum of all the forces and moments acting on an object sum to zero then an object has an acceleration of zero

Question 4

For equilibrium all forces have to be…

Answer 4

equal to zero in all 3 axes
Sum of the forces in y have to equal 0 and sum of forces in x have to equal 0
Further the sum of the moments have to equal 0

Question 5

In biomechanics it is important to consider that any applied force will be accompanied by…

Answer 5

a joint reaction force

Question 6

When pushing on a limb there is force where pressure is being applied and there is force…

Answer 6

at the joint to the rest of the body (force of one limb onto the other)
also there is force of gravity

Question 7

because the applied force is tending to cause a rotation about the joint it is creating a moment that must be

Answer 7

countered if the arm is to remain static

Question 8

Why don’t reaction forces cause moments?

Answer 8

Because they are acting right at the joint

Question 9

What is the reaction force in static analysis

Answer 9

the force from the rest of the body acting on this limb

Question 10

Why is static analysis important in biomechanics

Answer 10

• It is practially impossible to directly measure internal forces but the ability to solve for static equilibrium problems yields an estimate of these forces

Question 11

What are 3 applications of static analysis

Answer 11

• Ergonomics
• Static postures
• Sport (static situations)